So I have a Canon 400mm f/2.8 IS paired with a 1D mark IIn and when I shot football today in very hot sunny clear sky weather, I get some strange "swirly" bokeh with individual lines in some of the photos. It sort of depends which angle I shoot at (as it seems to appear more on photos where the background includes the audience). I am not shooting behind a net or anything.
Very swirly bokeh
http://i174.photobucket.com …e/Photography/sample3.jpg
Little less swirlyness:
http://i174.photobucket.com …re/Photography/sample.jpg
Can't see any swirly:
http://i174.photobucket.com …e/Photography/sample2.jpg
I shot soccer last week with the other body (the 1D mark II) in quite similarly sunny but not as hot weather and I didn't get this swirly effect. I'm not sure if the body is what's causing it.... probably not.
Soccer: http://www.flickr.com/photos/siaohd/4934370720/#/
Is this a normal phenomenon. All photos are f/2.8 and around 1/2000 shutter speed on AI SERVO. I used image stabilizer in football but I don't remember if I did for soccer. I am using the standard drop-in filter Canon gave me.